Needlepoint on chairs

These mahogany chairs have been in our family for several generations. I remember them in the living room of our house at 121 Nichols Street, Danvers. That was the new larger house we moved to 1959 (from our very small home at 120 Nichols Street). I imagine that these chairs were given to us by Granddaddy Nichols, from his house at 124 Nichols Street. I wonder if his wife Nellie ("Nana" to us) did the decorative needlework on these chairs. (See my previous post about Nana, and a hooked seat cover she had made.)

If Nana didn't do this needlework, who did?  I wonder if anyone else in our family knows. Please let me know (in the Comments, or by email) if you know more about this. Thanks!

P.S. I just reviewed an inventory of my father's furniture (a list made in 1990 at his home in Marblehead, MA, for insurance purposes). That list includes TWO pairs of mahogany side chairs with upholstered seats (one pair described as "Empire"; the other as "Federal"). The description for the Empire chairs mentions "slip upholstery needlepoint seats" and I see a penciled note ("by Nellie Nichols") in my handwriting in the margin. Aha! I wrote that note in 1992 when my sister and I were reviewing our father's list and he was downsizing prior to a move to California. Perhaps he told us that information? I don't recall. I now think those chairs went to my sister, and are NOT the chairs pictured here.

Here's the other description, which seems a better match for these chairs in my house: "Pair of Mahogany Federal Side Chairs with Carved Shield Backs above Upholstered Seats on Square Fontal Tapered Legs with Spade Feet."  See my photo below for a better view of the whole chair:

Note: the seat area is sunken; it is in need of repair underneath the needlework. Our cat used to love to curl up in that hollow! (We always kept a towel or blanket over the needlework, to protect it from cat claws and fur.)  A friend long ago recommended that I enroll in a local upholstery class that she was enjoying; she was sure I could fix those seats. Maybe so, but I didn't want to disturb the needlework, nor did I have the time or interest to do re-upholstery. In recent years, cat-less, we've kept a pile of folded blankets and quilts on top. These antique chairs are lovely, but not recommended for comfortable seating.